Advanced Progression Techniques
Advanced Progression Techniques
- Secondary progressions show slow inner development.
- Solar arc directions reveal life triggers.
Backlink: Progression Overview.
🧭 Technique Reference
| Technique | Key | Rate / rule |
|---|---|---|
| Secondary progression | 1 day = 1 year | Progressed Sun ≈ 0°59′/yr; Moon ≈ 1°/month |
| Tertiary progression | 1 day = 1 lunar (tropical) month | ≈ 13× faster than secondary |
| Minor progression | 1 lunar month = 1 year | ≈ 27.3 days of ephemeris per year of life |
| Solar-arc direction | all points + (progressed Sun − natal Sun) | ≈ 0°57′–1°01′/yr depending on birth season |
| Naibod direction | all points + 0°59′08″ × age | mean solar rate |
| Primary direction | 1° of right ascension ≈ 1 year (Ptolemy’s key) | rotation of the sphere; hardest to compute |
| Solar return | chart for the Sun’s exact return to its natal longitude | yearly |
Primary directions descend from Ptolemy (Tetrabiblos III.10) and were systematised by Placidus; secondary progressions became standard in the 19th–20th centuries.
Secondary progressions use the symbolic key one day after birth = one year of life (day-for-a-year). For age n years, compute the chart for JD_birth + n × (1 day) (more precisely n × 365.2422 / 365.2422 days → 1 ephemeris day per tropical year). Typical rates: progressed Sun ≈ 0°59′/yr; progressed Moon ≈ 11°–15°/yr (≈ 1° per month), completing a full circuit in ≈ 27.3 years and a full progressed lunation cycle in ≈ 29.5 years. Solar-arc directions add the progressed Sun’s arc to every natal point; Naibod arcs use the mean rate 0°59′08″ per year.
Sources (method)
- Claudius Ptolemy, Tetrabiblos (2nd c. CE), Book I — trans. F. E. Robbins, Loeb Classical Library 435 (1940), public-domain text at LacusCurtius: https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Ptolemy/Tetrabiblos/home.html
- Jean Meeus, Astronomical Algorithms, 2nd ed. (Willmann-Bell, 1998) — ch. 13 (coordinate transforms), ch. 47 (Moon, nodes, perigee/apogee)